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Archive for the 'CBER' Category

Planning for the Future – Resilience to Extreme Weather

By Claire Asher, on 15 January 2015

As climate change progresses, extreme weather events are set to increase in frequency, costing billions and causing immeasurable harm to lives and livelihoods. GEE’s Professor Georgina Mace contributed to the recent Royal Society report on “Resilience to Extreme Weather”, which predicts the future impacts of increasing extreme weather events, and evaluates potential strategies for improving our ability to survive, even thrive, despite them.

Extreme weather events, such as floods, droughts and hurricanes, are predicted to increase in frequency and severity as the climate warms, and there is some evidence this is happening already. These extreme events come at a considerable cost both to people’s lives, health and wellbeing, and the economy. Between 1980 and 2004, extreme weather is estimated to have cost around US$1.5 trillion, and costs are rising. A recent report by the Royal Society reviews the future risks of extreme weather and the measures we can take to improve our resilience.

The global insured and uninsured economic losses from the two biggest categories of weather-related extreme events. Royal Society (2014)

The global insured and uninsured economic losses from the two biggest categories of weather-related extreme events. Royal Society (2014)

Disaster risk is a combination of the likelihood of a particular disaster occurring and the impact on people and infrastructure. However, the impact will be influenced not only by the severity of the disaster, but by the vulnerability of the population and its infrastructure, a characteristic we have the potential to change. Thus, while it may be possible to reduce the frequency of disasters by reducing carbon emissions and slowing climate change, another key priority is to improve our own resilience against these events. Rather than just surviving extreme weather, we must adapt and transform.

The risks posed by climate change may be underestimated if exposure and vulnerability to extreme weather are not taken into account. Mapped climate and population projections for the next century show that the number of people exposed to floods, droughts and heatwaves will both increase and become more concentrated.

Exposure risk to floods and droughts in 2090. Royal Society (2014)

Exposure risk to floods and droughts in 2090. Royal Society (2014)

In their recent report, the Royal Society compared different approaches to increasing resilience to coastal flooding, river flooding, heatwaves and droughts. Overall, they found that a portfolio of defence options, including both physical and social techniques and those that utilise both traditional engineering solutions and more ecosystem based approaches. Broadly, approaches can be categorised as engineering, ecosystem-based, or hybrids of the two. Resilience strategies that incorporate natural ecosystems and processes tend to be more affordable and deliver wider societal benefits as well as simply reducing the immediate impact of the disaster.

Ecosystem-based approaches can take a variety of different forms, but often involve maintaining or improving natural ecosystems. For example … Large, intact tropical forests are important in climate regulation, flood and erosion management and … Forests can also act as a physical defence, and help to sustain livelihoods and provide resources for post-disaster recovery. Ecosystem-based approaches often require a lot of land and can take a long time to become established and effective, however in the long-term they tend to be more affordable and offer a wider range of benefits than engineering approaches. For this reason, they are often called ‘no regret’ options. Evidence for the effectiveness of different resilience strategies is highly varied. Engineered approaches are often well-established, with decades of strong research to back them up. In contrast, ecosystem approaches have been developed more recently and there is less evidence available on their effects. The Royal Society report indicates that for coastal flooding and drought, some of the most affordable and effective solutions are ecosystem-based, such as mangrove maintenance as a coastal defence and agroforestry to mitigate the effects of drought and maintain soil quality. In many situations, hybrid solutions may offer the best mixture of affordability and effectiveness.

It is crucial for governments to develop and implement resilience strategies and start building resilience now. This will be most effective if resilience measures are coordinated internationally, resources shared and where possible, cooperative measures implemented. By directing funds towards resilience-building, governments can reduce the need for costly disaster responses later. Governments can reduce the economic and human costs of extreme weather by focussing on minimising the consequences of infrastructure failure, rather than trying to avoid failure entirely. Prioritising essential infrastructure and focussing on minimising the harmful effects of extreme weather are likely to be the most effective approaches in preparing for future increases in extreme weather events.

Original Article:

() Resilience to
extreme weather

Changing Perspectives in Conservation

By Claire Asher, on 18 December 2014

Our views of the importance of nature and our place within have changed dramatically over the the last century, and the prevailing paradigm has profound influences on conservation from the science that is conducted to the policies that are enacted. In a recent perspectives piece for Science, GEE’s Professor Georgina Mace considered the impacts that these perspectives have on conservation practise.

Before the late 1960s, conservation thinking was largely focussed on the idea that nature is best left to its own devices. This ‘nature for itself‘ framework centred around the value of wilderness and unaltered natural reserves. This viewpoint stemmed from ecological theory and research, however by the 1970s it became apparent that human activities were having severe and worsening impacts on species, and that this framework simply wasn’t enough. This led to a shift in focus towards the threats posed to species by human activities and how to reduce these impacts, a ‘nature despite people‘ approach to conservation. This is the paradigm of protected areas and quotas, designed to reduce threats posed and ensure long-term sustainability.

Changing views of nature and conservation, Mace (2014)

Changing views of nature and conservation, Mace (2014)

By the 1990s, people had begun to appreciate the many and varied roles that healthy ecosystems play in human-wellbeing; ecosystem services are crucial to providing clean water, air, food, minerals and raw materials that sustain human activities. Shifting towards a more holistic, whole-ecosystem viewpoint which attempted to place economic valuations on the services nature provides, conservation thinking entered a ‘nature for people‘ perspective. Within this framework, conservationists began to consider new metrics, such as the minimum viable population size of species and ecosystems, and became concerned with ensuring sustainable harvesting and exploitation. In the last few years, this view has again shifted slightly, this time to a ‘people and nature‘ perspective that values long-term harmonious and sustainable relationships between humans and nature, and which includes more abstract benefits to humans.

Changing conservation paradigms can have a major impact on how we design conservation interventions and what metrics we monitor to assess their success. Standard metrics of conservation, such as the IUCN classification systems, can be easily applied to both a ‘nature for itself’ and a ‘nature despite people’ framework. In contrast, a more economic approach to conservation requires valuations of ecosystems and the services they provide, which is far more complex to measure and calculate. Even more difficult is measuring the non-economic benefits to human well-being that are provided for by nature. The recent focus on these abstract benefits may make the success of conservation interventions more difficult to assess under this framework.

The scientific tools, theory and techniques available to conservation scientists have not always kept up with changing conservation ideologies, and differing perspectives can lead to friction between scientists and policy-makers alike. In the long-term a viewpoint that recognises all of these viewpoints may be the most effective in directing and appraising conservation management. Certainly, greater stability in the way in which we view our place in nature would afford science the opportunity to catch-up and develop effective and empirical metrics that can be meaningfully applied to conservation.

Original Article:

() Science

The Best of Both Worlds:
Planning for Ecosystem Win-Wins

By Claire Asher, on 16 November 2014

The normal and healthy function of ecosystems is not only of importance in conserving biodiversity, it is of utmost importance for human wellbeing as well. Ecosystems provide us with a wealth of valuable ecosystem services from food to clean water and fuel, without which our societies would crumble. However it is rare that only a single person, group or organisation places demands on any given ecosystem service, and in many cases multiple stakeholders compete over the use of the natural world. In these cases, although trade-offs are common, win-win scenarios are also possible, and recent research by GEE academics investigates how we can achieve these win-wins in our use of ecosystem services.

Ecosystem services depend upon the ecological communities that produce them and are rarely the product of a single species in isolation. Instead, ecosystem services are provided by the complex interaction of multiple species within a particular ecological community. A great deal of research interest in recent years has focussed on ensuring we maintain ecosystem services into the long term, however pressure on ecosystem services worldwide lis likely to increase as human demands on natural resources soars. Ecosystem services are influenced by complex ecosystem feedback relationships and food-web dynamics that are still relatively poorly understood, and increased pressures on ecosystems may lead to unexpected consequences. Although economical signals respond rapidly to global and national changes, ecosystem services are thought to lag behind, often by decades, making it difficult to predict and fully understand how our actions are influences the availability of crucial services in the future.

Trade-offs in the use of ecosystem services occur when the provision of one ecosystem service is reduced by increased use of another, or when one stakeholder takes more of an ES at the expense of other stakeholders. However, this needn’t be the case – in some scenarios it is possible to achieve win-win outcomes, preserving ecosystem services and providing stakeholders the resources they need. Although attractive, win-win scenarios may be difficult to achieve without carefully planned interventions, and recent research from GEE indicates they are not as common as we might like.

In a comprehensive meta-analaysis of ecosystem services case studies from 2000 to 2013, GEE academics Prof Georgina Mace and Dr Caroline Howe show that trade-offs are far more common than win-win scenarios. Across 92 studies covering over 200 recorded trade-offs or synergies in the use of ecosystem services, trade-offs were three times more common than win-wins. The authors identified a number of factors that tended to lead to trade-offs rather than synergies. In particular, if one or more of the stakeholders has a private interest in the natural resources available, trade-offs are much more likely – 81% of cases like this resulted in tradeoffs. Furthermore, trade-offs were far more common when the ecosystem services in question were ‘provisioning’ in nature – products we directly harvest from nature such as food, timber, water, minerals and energy. Win-wins are more common when regulating (e.g. nutrient cycling and water purification) or cultural (e.g. spiritual or historical value) ecosystem services are in question. In the case of trade-offs, there were also factors that predicted who the ‘winners’ would be – winners were three times more likely to hold private interest in the natural resource in question, and tended to be wealthier than loosing stakeholders. Overall, there was no generalisable context that predicted win-win scenarios, suggesting that although trade-off indicators may be useful in strategic planning, the outcome of our use of ecosystem services is not inevitable, and win-wins are possible.

They also identified major gaps in the literature that need to be addressed if we are to gain a better understanding of how win-win scenarios may be possible in human use of ecosystems. In particular, case studies are currently only available for a relatively limited geographic distribution, and tend to focus of provisioning services. Thus, the lower occurrence of trade-offs for regulating and cultural ecosystem services may be in part a reflection of a paucity of data on these type of services. Finally, relatively few studies have attempted to explore the link between trade-offs and synergies in ecosystem services and the ultimate effect on human well-being.

Understanding how and why trade-offs and synergies occurs in our use of ecosystem services will be valuable in planning for win-win scenarios from the outset. Planning of this kind may be necessary if we are to achieve and maintain balance in our use of the natural world in the future.

Original Article:

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This research was made possible by support from the Ecosystem Services for Poverty Alleviation (ESPA) programme, which is funded by the Natural Environment Research Council (NERC), the Economic and Social Research Council (ESRC), and the UK Department for International Development (ERC)

Life Aquatic:
Diversity and Endemism in Freshwater Ecosystems

By Claire Asher, on 6 November 2014

Freshwater ecosystems are ecologically important, providing a home to hundreds of thousands of species and offering us vital ecosystem servies. However, many freshwater species are currently threatened by habitat loss, pollution, disease and invasive species. Recent research from GEE indicates that freshwater species are at greater risk of extinction than terrestrial species. Using data on over 7000 freshwater species across the world, GEE researchers also show a lack of correlation between patterns of species richness across different freshwater groups, suggesting that biodiversity metrics must be carefully selected to inform conservation priorities.

Freshwater ecosystems are of great conservation importance, estimated to provide habitat for over 125,000 species of plant and animal, as well as crucial ecosystem services such as flood protection, food, water filtration and carbon sequestration. However, many freshwater species are threatened and in decline. Freshwater ecosystems are highly connected, meaning that habitat fragmentation can have serious implications for species, while pressures such as pollution, invasive species and disease can be easily transmitted between different freshwater habitats. Recent work by GEE academics Dr Ben Collen, in collaboration with academics from the Institute of Zoology, investigated the global patterns of freshwater diversity and endemism using a new global-level dataset including over 7000 freshwater mammals, amphibians, reptiles, fishes, crabs and crayfish. Many freshwater species occupy quite small ranges and the authors were also interested in the extent to which species richness and the distribution threatened species correlated between taxonomic groups and geographical areas.


The study showed that almost a third of all freshwater species considered are threatened with extinction, with remarkably little large-scale geographical variation in threats. Freshwater diversity is highest in the Amazon basin, largely driven by extremely high diversity of amphibians in this region. Other important regions for freshwater biodiversity include the south-eastern USA, West Africa, the Ganges and Mekong basins, and areas of Malaysia and Indonesia. However, there was no consistent geographical pattern of species richness in freshwater ecosystems.

Freshwater species in certain habitats are more at risk than others – 34% of species living in rivers and streams are under threat, compared to just 20% of marsh and lake species. It appears that flowing freshwater habitats may be more severely affected by human activities than more stationary ones. Freshwater species are also consistently more threatened than their terrestrial counterparts. Reptiles, according to this study, are particularly at risk from extinction, with nearly half of all species threatened or near threatened. This makes reptiles the most threatened freshwater taxa considered in this analysis. The authors identified key process that were threatening freshwater species in this dataset – habitat degradation, water pollution and over-exploitation are the biggest risks. Habitat loss and degradation is the most common threat, affecting over 80% of threatened freshwater species.

That there was relatively little congruence between different taxa in the distribution of species richness and threatened species in freshwater ecosystems suggests that conservation planning that considers only one or a few taxa may miss crucial areas of conservation priority. For example, conservation planning rarely considers patterns of invertebrate richness, but if these groups are affected differently and in different regions than reptiles and amphibians, say, then they may be overlooked in initiatives that aim to protect them. Further, different ways to measure the health of populations and ecosystems yield different patterns. The metrics we use to identify threatened species, upon which conservation decisions are based, must be carefully considered if we are to suceeed in protecting valuable ecosystems and the services the provide.

Original Article:

() Global Ecology and Biogeography

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This research was made possible by funding from the Rufford Foundation and the European Commission

PREDICTS Project: Land-Use Change Doesn’t Impact All Biodiversity Equally

By Claire Asher, on 13 October 2014

Humans are destroying, degrading and depleting our tropical forests at an alarming rate. Every minute, an area of Amazonian rainforest equivalent to 50 football pitches is cleared of its trees, vegetation and wildlife. Across the globe, tropical and sub-tropical forests are being cut down to make way for expanding towns and cities, for agricultural land and pasture and to obtain precious fossil fuels. Even where forests remain standing, hunting and poaching are stripping them of their fauna, degrading the forest in the process. Habitat loss and degradation are the greatest threats to the World’s biodiversity. New research from the PREDICTS project investigates the patterns of species’ responses to changing land-use in tropical and sub-tropical forests worldwide. In the most comprehensive analysis of the responses of individual species to anthropogenic pressures to date, the PREDICTS team reveal strong effects of human disturbance on the geographical distribution and abundance of species. Although some species thrive in human-altered habitats, species that rely on a specific habitat or diet, and that tend to have small geographical ranges, are particularly vulnerable to habitat disturbance. Understanding the intricacies of how different species respond to different types of human land-use is crucial if we are to implement conservation policies and initiatives that will enable us to live more harmoniously with wildlife.

Red Panda (Ailurus fulgens)

Habitat loss and degradation causes immediate species losses, but also alters the structure of ecological communities, potentially destabilising ecosystems and causing further knock-on extinctions down the line. As ecosystems start to fall apart, the valuable ecosystem services we rely on may also dry up. There is now ample evidence that altering habitats, particularly degrading primary rainforest, has disastrous consequences for many species, however not all species respond equally to land-use change. The functional traits of species, such as body size, generation time, mobility, diet and habitat specificity can have a profound impact on how well a species copes with human activities. The traits that make species particularly vulnerable to human encroachment (slow reproduction, large body size, small geographical range, highly specific dietary and habitat requirements) are not evenly distributed geographically. Species possessing these traits are more common in tropical and sub-tropical forests, areas that are under the greatest threat from human habitat destruction and loss of vegetation over the coming decades. The challenge in recent years, therefore, has been developing statistical models that allow us to investigate this relationship more precisely, and collecting sufficient data to test hypotheses.

There are three key ways we might chose to investigate how species respond to land-use change. Many studies have investigated species-area relationships, which model the occurrence or abundance of species in relation to the size of available habitat. These studies have revealed important insights into the damage caused by habitat fragmentation, however they rarely consider how different species respond differently. Another common approach uses species distribution models to predict the loss of species in relation to habitat and climate suitability. These models can be extremely powerful, but require large and detailed datasets that are not available for many species, particularly understudied creatures such as invertebrates. The PREDICTS team therefore opted for a third option to investigate human impacts on species. The PREDICTS project has collated data from over 500 studies investigating the response of individual species to land-use change, and their database now includes over 2 million records for 34,000 species. Using this extensive dataset, the authors were able to model the relationship between land-use type and both the occurrence and abundance of species. One of the huge benefits of this approach is that their dataset enabled them to investigate these relationships in a wide range of different taxa, including birds, mammals, reptiles, amphibians and the often neglected invertebrates.

Modelling Biodiversity

Sunbear (Helarctos malayanus)
image used with permission from
Claire Asher (Curiosity Photographic)

The resulting model included the responses of nearly 4000 different species across four measures of human disturbance; lang-use type, forest cover, vegetation loss and human population density. The vast dataset, the PREDICTS team were able to compare the responses of species in different groups (birds, mammals, reptiles and amphibians, invertebrates, between habitat specialists and generalists and between wide- and narrow-raging species. Their results revealed a complex interaction between these factors, which influenced the occurrence and the abundance of species in different ways.

In general human-dominated habitats, such as urban and cropland environments, tended to harbour fewer species than more natural, pristine habitats. Community abundance in disturbed habitats was between 8% and 62% of the abundance found in primary forest, and urban environments were consistently the worst for overall species richness. In these environments, human population density and a lack of forest cover were key factors reducing the number of species. Human population density could impact species directly through hunting, or more indirectly through expanding infrastructure. However, these factors impact different species in different ways, so the authors next investigated different taxa separately.

Birds appear to be particularly poor at living in urban environments, most likely because they respond poorly to increases in human population. Forest specialists and narrow-ranged birds fare especially badly in urban environments; only 10% of forest specialists found in primary forest are able to survive in urban environments. Although the effect was less extreme, mammals were also less likely to occur in secondary forest and forest plantations than primary forest, and forest specialists were particularly badly affected.

Urban Pests
Although many species were unable to exist in disturbed habitats, those species that persisted were often more abundant in human-modified habitats than pristine environments. This isn’t particularly surprising – some species happen to possess characteristics that make them well suited to urban and disturbed landscapes; these are often the species that we eventually start to consider a pest because they are so successful at living alongside us (think pigeons, rats, foxes). These species tend to be wide-ranging generalists, although sometimes habitat specialists do well in human-altered habitats if we happen to alter the habitat in just the right. Pigeons, for example, are adapted to nesting on cliffs, which our skyscrapers and buildings inadvertently mimic extremely well. The apparent success of some species in more open habitats such as cropland and urban environments might also be partly caused by increased visibility – it’s far easier to see a bird or reptile in an urban environment than dense primary forest! This doesn’t explain the entire pattern, however, and clearly some species are simply more successful in human-altered habitats. They are in the minority, though.

Do Reptiles Prefer Altered Habitats?
One interesting finding was that for herptiles (reptiles and amphibians), more species were found in habitats with a higher human population density. This rather unexpected relationship might reflect a general preference in herptiles for more open habitats. Consistent with this, the authors found fewer species in pristine forest than secondary forest. However, upon closer inspection the authors found that herptiles do not all respond in the same way. Reptiles showed a U-shaped relationship with human population density – the occurrence of species was highest when there were either lots of people or no people at all. By contrast, amphibians showed a straight relationship, with increases in human population density being mirrored by increases in the number of species present. This highlights the importance of investigating fine-scale differences between species in their responses to human activities.

Filbert Weevil (Curculio occidentis)

Consistent with previous studies, the traits of species were very important in determining whether a species was found in human-altered habitats. Narrow-ranging species were much less likely to occur in any habitat than wide-ranging ones, but this difference was particularly clear for croplands, plantation forests and urban habitats. The extent of human impact was also a key factor determining the occurrence of species in different habitats. Forest cover, human population density and NDVI (a measure of vegetation loss taken from remote sensing) all reduced the number of species present. Measures of disturbance and species characteristics do not act in isolation – the best models produced by the PREDICTS team included interactions between these variables. Invertebrate numbers were lowest in areas of high human population density and high rates of vegetation loss.

This study is the first step in more detailed, comprehensive analyses of the responses of species to human activities. The power of this study comes not only from it’s large dataset and broad spectrum of taxonomic groups, but also from it’s ability to directly couple land-use changes with species’ traits such as range-size and habitat specialism. The authors say that the next major step would be to incorporate interactions between species in these models – the community structure of an ecosystem can have profound effects on the species living in it, and changes in the abundance of any individual species does not happen in isolation from the rest of the community.

Check out the PREDICTS Project for more information!

Original Article:

() Proc. R. Soc. B

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This research was made possible by funding from the Natural Environment Research Council (NERC), and the Biotechnology and Biological Sciences Research Council (BBSRC).

Applying Metabolic Scaling Laws to Predicting Extinction Risk

By Claire Asher, on 25 September 2014

The Earth is warming. That much were are now certain of. A major challenge for scientists hoping to ameliorate the effect of this on biodiversity is to predict how temperature increases will affect populations. Predicting the responses of species living in complex ecosystems and heterogenous environments is a difficult task, but one starting point is to begin understanding how temperature increases affect small, laboratory populations. These populations can be easily controlled, and it is hoped that the lessons learned from laboratory populations can then begin to be generalised and applied to real populations. Recent research from GEE academics attempted to evaluate the predictive power of a simple metabolic model on the extinction risk of single-celled organisms in the lab. Their results indicate that simple scaling rules for temperature, metabolic rate and body size can be extremely useful in predicting the extinction of populations, at least in laboratory conditions.

Current estimates suggest that over the next 100 years we can expect a global temperature rise of between 1.1°C and 6.4°C. This change will not be uniformly distributed across different regions however, with some areas expected to experience warming at twice the global average rate. Temperature is known to be a crucial component in some of the most basic characteristics of life – metabolism, body size, birth, growth and mortality rates. These characteristics have been shown to scale with temperature in an easily predictable way, formalised in the Arrhenius equation. This equation yields a roughly 3/4 scaling rule, so that as temperature increases, metabolism increases around 75% as fast. This relationship appears to hold true for a variety of taxa with different life histories and positions in the food chain. Models based upon this rule can be designed that are very simple, which makes it easy for scientists to collect the data needed to plug into the model. But are they accurate in predicting extinction?

Recent research conducted by GEE and ZSL academics Dr Ben Collen and Prof. Tim Blackburn, in collaboration with the University of Sheffield and The University of Zurich, investigated the predictive power of simple metabolic models on extinction risk in a single-celled protist Loxocephallus. They first collected data on the population and extinction dynamics of a population held at constant temperature. This data was fed into a model based on scaling laws for metabolic rates and temperature, which in turn attempted to predict extinction risk under different temperature changes. The researchers tested how real protists responded to temperature changes – for 70 days they monitored populations of the protist Loxocephallus under either decreases or increases in temperature. Populations began at 20°C and increased to 26°C or decreased to 14°C at different rates (0.5°C, 0.75°C, 1.5°C or 3°C each week). Most populations eventually went extinct, but these extinctions happened sooner in hotter environments, and mean temperature showed a strong correlation with the date at which the population went extinct. Extinction tended to happen sooner in populations subjected to more rapid warming.

None of this is particularly surprising, but what the researchers found when they ran their models was that, even with relatively minimal data to start out with (population dynamics under constant ‘normal’ conditions), and using only simple scaling laws to predict extinction, their model was able to accurately predict when populations would go extinct under different warming or cooling conditions, with an accuracy of 84%. One important factor was the specifics of the temperature changes that were input into the model – using average temperature across the experiment rather than actual temperature changes produced much less accurate results.

This research is a first step in creating models that may help us predict the future extinction dynamics of wild populations subjected to unevenly distributed climatic warming over coming decades. It is a long way from a simple model of a laboratory population to a model that can accurately predict the future of complex assemblages of wild animals that are also subject to predation, disease and a healthy dose of luck. But the fact that these models can work for simple systems in laboratory conditions is a great first start – if they didn’t work for these populations, we could be fairly sure they wouldn’t generalise to natural populations. This shows that simple phenomenological models based on basic metabolic theory can be useful to understand how climate change will effect populations.

Original Article:

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This research was made possible by funding from the Natural Environment Research Council (NERC).

Extinction and Species Declines:
Defaunation in the Anthropocene

By Claire Asher, on 18 August 2014

We are in the grips of a mass extinction. There have been mass extinctions throughout evolutionary history, what makes this one different is that we’re the ones causing it. A recent review paper from GEE’s Dr Ben Collen discusses the current loss of biodiversity and suggests that our main concerns are species and population declines, which alter ecosystem dynamics and threaten our food, water and health. Understanding the drivers of local declines is more complex than understanding species extinction, but may be more pertinent to our ongoing health and survival.

The history of life on Earth has been punctuated by five mass-extinction events; from the Ordovician-Silurian extinction that killed 85% of sea life 443 million years ago, to the famous Cretaceous-Tertiary extinction that wiped out the dinosaurs 65 million years ago, mass extinctions have been a part of life. However, we are now in the middle of the sixth mass extinction event, and we’re the ones who are causing it. The last 500 years has seen humans cause a wave of extinctions of such speed and magnitude that it rivals the big five extinction events of the past.

Defaunation in the Anthropocene

Like other mass extinctions, the Anthropocene extinction event is affecting all taxonomic groups, although some are being hit harder than others. Since 1500, over 300 terrestrial vertebrates, 90 fish and nearly 400 are known to have been driven to extinction (although the real figures are likely much higher!). A conservative estimate suggests that we may be losing anywhere between 10,000 and 60,000 species each year. Many of these species go extinct before we ever even get a chance to identify them. Extinction is not evenly distributed, though – amphibians appear to be worse affected than birds, for example. Perhaps more worrying, many remaining species are suffering severe population declines. Globally, terrestrial vertebrate populations show declines of 25%, and 67% of monitored invertebrate populations are declining by 45%! The loss of species from ecosystems, either through local population declines or species extinction, will undoubtedly disrupt ecosystem function and the key ecosystem services humans rely on for survival and well being.

Scientists have coined the term ‘defaunation’ to include the extinction of species and populations as well as local declines in abundance. Defaunation can be thought of as deforestation for animals. It is an important point to make that although species extinctions are conspicuous and striking, the real damage to ecosystem function happens a long time before the final extinction event. Declines in populations will alter community composition far more than the final loss of the few remaining individuals of a population, and further, population declines have the potential to be reversed, if we act quickly enough!

Predicting Patterns of Defaunation

If we are to halt or even slow the current mass extinction, we need to identify both the causes of defaunation and the traits that make certain species so vulnerable to human disruption. The main drivers of defaunation are overexploitation of species, habitat destruction and introduced invasive species. These threats have all increased in severity over the past decade and look set to continue. In addition to these long-term threats, climate change is rapidly becoming the biggest threat to biodiversity. Most threatened species are under pressure from multiple human threats, but our understanding of the complex interactions and feedback loops between different threats is still in it’s infancy. It’s clear though that these threats do not act in isolation; a species trying to track suitable habitat as it moves with climate change will find that task much harder if habitat loss and fragmentation is also occurring.

Researchers have highlighted a number of life history and biological traits that tend to make species more vulnerable to human impacts. For example, species that have a small geographic range, large body size and produce just a few offspring after a long-development process, are more likely to be threatened with extinction due to human activities. However, our understanding of the traits that influence species’ extinction risk doesn’t help conservation as much as you might expect, because the relationship between these traits and extinction risk is often idiosyncratic and highly context-dependent. These relationships may also be more variable and weaker for individual populations than for whole species, making population declines more difficult to predict than whole-species extinctions. Defaunation, ultimately, is a synergistic function of the traits a species possess and the nature of the threat(s) it is exposed to.

Disrupting Ecosystems and Communities

The loss of biodiversity through defaunation is not just a concern because of the aesthetic appeal of an individual species, or of a world rich in diversity in general. It is also a major concern because defaunation will likely have a negative impact on the ecosystem goods and services upon which we rely upon for our wellbeing and survival. In fact, biodiversity loss is thought to be comparable to other threats such as pollution in terms of it’s impact on ecosystem function. Defaunation can be expected to have a negative impact on our food, water and health, as well as our psychological wellbeing.

Food

Insect pollination is required for the continued production of 75% of the World’s crops, and is responsible for 10% of the economic value of the entire World’s food supply. Declines in pollinators are now a major problem, particularly in Northern Europe and the USA, and have been linked to declines in insect-pollinated plants. Biodiversity, particularly of small vertebrates, is provides crucial pest control services, valued at around $4.5 billion a year in the USA alone. Declines in small vertebrate populations are linked to cascading changes in the whole ecosystem which allow increases in pest abundance and, consequently, a loss of plant biomass. If the plant in question is a crop or food source, the results can be catastrophic.

Nurtient Cycling and Decomposition

Invertebrates are also very important for their roles in decomposition and nutrient cycling. Defaunation can reduce these important services, and cause changes in the patterns of nutrient cycling that can have knock-on effects on a huge variety of ecosystems. Likewise, large vertebrates that roam large home ranges are important in connecting ecosystems and transferring energy between them, and yet these species are often the most severely impacted by human activities.

Water

Another key ecosystem service is the provision of clean, fresh water. Research has shown that declines in amphibian populations can result in increases in algae, reduced nitrogen uptake and changes to oxygen availability in the water. This too will likely have major knock-on effects for other species (including ourselves!).

Health and Medicine

Finally, we can expect defaunation to negatively affect our health. Species that are more robust to human disturbance are often also better at carrying and transmitting zoonotic diseases (diseases that are carried by animals and transferred to humans), and altering ecosystem dynamics can change behaviours that influence transmission rates. Defaunation is likely to also reduce the availability of pharmaceutical compounds and alter the dynamics of disease regulation. All of this may mean that defaunation leads to an increase disease and a reduction in the availability of therapeutic compounds.

The impact of defaunation is less about the absolute loss of biodiversity and more about the local shifts in species composition and functional groups, which alter ecosystem function and ultimately, our food, water and health. However, reductions in species exploitation and land-use change are two feasible actions that can be achieved rapidly and may buy us enough time to address other drivers of defaunation such as climate change. Globally, we need to reduce and more evenly distribute our consumption if we are to change current trends in defaunation, and open the possibility for refaunation.

Original Article:

() Science

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NSF

This research was made possible by funding from the Natural Environment Research Council (NERC), the National Council for Scientific and Technological Development (CNPQ), the Foundation for the Development of UNESP, the Sao Paolo Research Foundation, the Joint Nature Conservation Committee (JNCC), the National Science Foundation (NSF) and the National Autonomous University of Mexico/a>.

It Pays to Be Different:
Evolutionary Distinctiveness and Conservation Priorities

By Claire Asher, on 15 July 2014

The world is currently experiencing an extinction crisis. A mass extinction on a scale not seen since the dinosaurs. While conservationists work tirelessly to try and protect the World’s biodiversity, it will not be possible to save everything, and it is important to focus conservation efforts intelligently. Evolutionary distinctiveness is a measure of how isolated a species is on it’s family tree – how long ago it split off from its nearest living relative. A recent paper co-authored by UCL GEE’s Dr David Redding, published in Current Biology, assessed how effective evolutionary distinctiveness is a tool for identifying bird species of conservation priority. Current conservation efforts are missing some of the most evolutionarily distinct species.

Evolutionary distinctiveness (ED) is measured as the distance along the evolutionary tree from one species to it’s nearest relative. It can be used as a measure of how much evolutionary ‘information’ would be lost if this species were to become extinct. We have good estimates of these distances for birds as we have been able to put dates on the evolutionary tree based on fossil records and molecular data. A recent analysis of nearly 10,000 known bird species, by researchers at Yale University, Imperial College London, University of Sheffield, Simon Fraser University, University of Tasmania and University College London, showed some patterns we might have expected, for example, evolutionary distinctiveness is highest in isolated regions (e.g. Australia, New Zealand and Madagascar) and regions with higher species richness tended to have more evolutionary distinct birds. However, there were also some unexpected results. For example, ED wasn’t strongly related to latitude, a pattern predicted by the idea that the tropics act as a ‘museum’ for ancient lineages, nor was ED related to a species’ range-size, which has previously been predicted theoretically.

Evolutionary distinctiveness showed little relationship with conservation status – some of the most threatened distinct species are found outside of biodiverse regions that are usually the target of conservation efforts. This means that, when we consider only species richness or total biodiversity to identify regions to conserve, we may be missing a great deal of evolutionary information. Instead, basing areas of conservation priority on the evolutionary distinctiveness of their flora and fauna may offer a more efficient and effective way to maximise the evolutionary variation we keep.

The paper also released the first formal list of ‘EDGE birds’ – EDGE stands for “Evolutionary Distinctive and Globally Endangered” and is a metric combining ED with the IUCN Red List. The list includes the Giant Ibis, the New Caledonian Owlet-Nightjar, the California Condor, the Kakapo, the Philippine Eagle, the Christmas Island Frigatebird and the Kagu, all of which are listed as either Critically Endangered or Endangered.

The most evolutionary distinct birds include both common species and rare species, both isolated and wildly distributed species, and are found in almost every environment on Earth. Current conservation efforts that focus on tropical regions with high species richness may be neglecting many evolutionary distinct species, whose extinction would represent the loss of a great deal of ‘evolutionary information’. Evolutionary distinctiveness could offer a powerful tool to supplement current criteria for identifying conservation priorities.

Original Article:

() Current Biology

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This research was made possible by funding from the Natural Environment Research Council (NERC), the Natural Sciences and Engineering Research Council (NSERC), the National Science Foundation, and the National Aeronautics and Space Administration (NASA)

Synthetic Biology and Conservation

By Claire Asher, on 7 July 2014

Synthetic biology, a hybrid between Engineering and Biology, is an emerging field of research promising to change the way we think about manufacturing, medicine, food production, and even conservation and sustainability. Oryx front cover
A review paper released this month in Oryx, authored by Dr Kent Redford, Professor William Adams, Dr Rob Carlson, Bertina Ceccarelli and CBER’s Professor Georgina Mace, discusses the possibilities and consequences of synthetic biology for biodiversity conservation. Synthetic biology aims to engineer the natural world to generate novel parts and systems that can be used to tackle real world problems such as genetic disease, food security, invasive species and climate change. It’s implications are far reaching, and although research in synthetic biology began decades ago, conservation biologists have only recently begun to take notice and appreciate it’s relevance to the conservation of biological diversity. A conference organised by the Wildlife Conservation Society in 2013 discussed the relationship between synthetic biology and conservation, and included speakers from both fields.

Finding Common Ground
It might be surprising to find that, despite a similar background in biological research, the shared knowledge and language of conservationists and synthetic biologists is relatively limited. Further, many synthetic biologists come from an engineering background, with little training in ecology. This can make communication between scientists in these fields more difficult, and may have slowed the pace at which synthetic biology has interfaced with conservation science. The two disciplines also employ different methods and think about nature in different ways. Synthetic biology is largely conducted within large, highly controlled laboratory conditions, whilst ecologists work on complex, interrelated natural systems with a major social and political component. Conservationists, working in a high-stakes field and learning from past mistakes, tend to be quite risk-averse in their practice of conservation, whilst synthetic biologists, working in a new science with much to gain from experimentation, tend to be more in favour of taking large risks. They may also have different outlooks on the future of biodiversity – conservations tend to be more pessimistic about the future, mourning past biodiversity loss, whilst synthetic biologists have an upbeat attitude, envisaging the applications of exciting research. Despite these (extremely generalised) differences, the conference revealed interest and excitement on both sides about the possibility of collaborating, and a mutual appreciation that the major challenges of the Anthropocene are human influences on climate, biodiversity and ecosystems. Finding practical, long-lasting and safe solutions to the plethora of challenges currently facing humanity, is of mutual interest.

Mitigating Risks and Maximising Benefits
The possible applications of synthetic biology to conservation are many. Synthetic biology might enable us to develop more efficient methods of energy production, freeing up habitat to recover. It could mitigate the effects of greenhouse gas emissions by releasing carbon-consuming algae. It could revive extinct species such as mammoths and dodos in a process known as ‘de-extinction’. It could engineer coral that is tolerant to increases in ocean temperature and acidity, conditions which are predicted to worsen under climate change. It could help to control or eradicate invasive species. It could restore degraded land and water for agriculture, sparing the need to destroy more natural habitat. It could even create pesticide- and parasite-resistant bees that can continue to pollinate our crops generations into the future.

However, he potential risks of synthetic biology to conservation are as many as the potential benefits. The effects of synthetic biology on conservation could be direct, (e.g. engineering resistant species), or they could be indirect (e.g. changes in land use). These effects could be negative, for example, if they lead to land use change of primary habitat as has been associated with GMOs and biofuels. They could also be positive, for example if they reduce the impact of human activities, allowing habitat to recover to its natural state. Synthetic biology might lead to unexpected impacts on ecosystem dynamics and risks the unintended escape of novel organisms into open ecosystems. Releasing synthetically engineered organisms into wild environments could alter ecosystems, reduce natural genetic variability or lead to hybridisation events that might display native flora and fauna, and generate new invasive species. Synthetic biology might also distract attention and funds from more traditional conservation efforts, whilst attracting protest from human rights and environmental organisations. Both conservationists and synthetic biologists are conscious of these potential risks, and are committed to careful consideration on a case-by-case basis. Not all synthetic biology is the same; some could be of huge potential benefit to conservation and sustainability whilst carrying minimal risks, and it is these that we should pursue.

Original Article:

() Oryx

Technology for Nature?

By Claire Asher, on 16 June 2014

Many of our greatest technological advances have tended to mark disaster for nature. Cars guzzle fossil fuels and contribute to global warming; industrialised farming practices cause habitat loss and pollution; computers and mobile phones require harmful mining procedures to harvest rare metals. But increasingly, ecologists and conservation biologists are asking whether we can use technology to help nature. On 10th June 2014, UCL’s Center for Biodiversity and Environment Research (CBER) hosted academics from the National Museum of Natural History, Paris, the Zoological Society of London and the Natural History Museum, London for a workshop on “Technology for Nature”. The workshop formed part of a series of public debates and workshops organised in collaboration with the French Embassy, around the theme of the ‘State of Nature’.

Technology for Nature Workshop

The workshop discussed some of the latest technologies available to monitor biodiversity and how these might be harnessed in combination with citizen science to better understand the natural world around us. Citizen science, which engages members of the public in collecting and processing data about nature, is a powerful tool enabling scientists to collect much larger quantities of data on populations of key species. Citizen science projects not only provide biologists with vastly more data than they could ever hope to collect on their own, but it also serves to engage members of the public with the natural world, and raise awareness of key environmental issues.

Following the workshop, UCL also hosted an evening debate in collaboration with colleagues at the French Embassy, London. Professor Romain Julliard from the National Museum of Natural History, Paris, and Professor Kate Jones from UCL’s CBER discussed how new technologies can be used to understand and predict the impact of humans on the natural world, and whether these technologies can be used to inspire and engage the public with the environment around them.

Technology for Nature Debate

Professor Julliard is the Scientific Director of Vigie Nature, a project to monitor trends in various widespread species including butterflies, birds, bees and flowers, using citizen scientists in France. Professor Jones holds the chair of Ecology and Biodiversity at UCL and the Zoological Society of London, and has been involved in a number of projects utilising citizen scientists to monitor populations of bats both in the UK and across Europe. She started the iBats project, which uses volunteers to collect acoustic recordings of bat calls which a computer algorithm can then use to identify the species, and has used citizen science to process data from this project through Bat Detective.

The meeting last week brought together academics from a range of different institutions with a shared interest in monitoring biodiversity to better understand how humans are impacting upon it. We hope this will lead to new projects and collaborations to monitor biodiversity and gain vital data that is needed to assess and ultimately mitigate our impact on the animals and plants we share the planet with.